iOS 15.7.4 (build 19H321) is an official Apple over-the-air update for the iPhone 6s+, released on 2023-03-27T17:12:50Z. The update package is 3.53 GB. This is a delta (partial) update that requires 12.1.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 03117b9be082b5ec7da64ad4531a115db55f257e.zip.